Process for gas-free packaging of molten alkali metal

ABSTRACT

A process for the gas-free packaging of a molten alkali metal in a can capable of accepting a clamp-on lid, said process comprising filling said can with said molten metal, applying a lid to said can, closing said can by clamping said lid to said can, inverting the resulting closed can so that the exposed surface of said lid faces downward, and cooling the inverted can. The can including its contents are useful in metallurgical processes.

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PROCESS FOR GAS-FREE PACKAGING OF MOLTEN ALKALI METAL Inventors: Helmut Knorre, Seligenstadt; Peter Leidl, Grossauheim, both of Germany Deutsche Gold-Und Silber-Scheideanstalt vormals Roessler, Frankfurt am Main, Germany Filed: Mar. 5, 1973 Appl. No.: 337,985

Assignee:

U.S. Cl 53/7, 53/25, 53/37 Int. Cl B65b 31/02 Field of Search 53/5, 6, 7, 8, 9, 12, 22 R,

References Cited UNITED STATES PATENTS 6/1918 Ball 53/25 X 2,949,710 8/1960 Wheeler 53/37 X Primary ExaminerTravis S. McGehee Attorney, Agent, or FirmBrowne, Beveridge, DeGrandi & Kline [57] ABSTRACT A process for the gas-free packaging of a molten alkali metal in a can capable of accepting'a clamp-0n lid, said process comprising filling said can with said molten metal, applying a lid to said can, closing said can by clamping said lid to said can, inverting the resulting closed can so that the exposed surface of said lid faces downward, and cooling the inverted can. The can including its contents are useful in metallurgical processes.

2 Claims, N0 Drawings PROCESS FOR GAS-FREE PACKAGING OF MOLTEN ALKALI METAL Introduction of a lumpy alkali metal into a melt of 5 other metals is generally not possible, since the alkali metal remains on the surface of the melt because of the low specific gravity of the metal. The alkali metal is then subject to ignition on the surface of the melt. Also, the alkali metal must be as free as possible of oxide impurities, since for example, sodium hydroxide or sodium carbonate in an aluminum containing melt would cause changes which would result in embrittlement and shrinkage of the alloy.

Consequently, air and moisture sensitive metallurgical additives such as the alkali metals have been packaged and stored in aluminum cans having clampable lids. The cans with their lids and contents are then added to the metallurgical melt.

Such packages are then generally prepared by positioning a can with its opening upward, and filling the can with molten metal. A lid is then fastened on the filled can.

It was found, however, that the alkali metal in packages filled in this manner partially oxidizes after more or less prolonged storage. It was also found that the alkali metal contained an alkali-hydroxide and/or carbonate on its surface, which resulted in'adverse effects on the metallurgical melts.

then inverted so that the surface of the lid on the outside of the can faces downward. The inverted can is then cooled to ambient temperature in the conventional manner. Upon solidifying the alkali metal, a tight seal is formed, which of course is necessary during prolonged storage.

Preferably, the can and its lid are metallic, and the metal of the can and lid are the same as at least one metal in the melt to which they are to be added. For example, in a process for preparing a silumin alloy. the can and its lid are generally comprised of aluminum, and the contents of the can comprised of sodium or lithium. Such a package is particularly adapted for use in metallurgical processes since the likelihood of introducing undesirable impurities into a melt can be practically eliminated.

in a particularly preferred embodiment of this invention, an air and gas-tight package is prepared by providing the can with a loosely fitting lid after the can is filled with molten metal. The can with the loosely fitting lid is then inserted in a support swivelable by 180 and disposed in a heatable vacuum chamber. The chamber is then evacuated while maintaining the alkali metal in molten form. The container with the loosely fitting lid is allowed to cool after the support is inverted by swiveling 180. The vacuum is relieved (broken), and the Thus, there exists a need in the art for a method of lid is then clamped to the can.

This invention is particularly advantageous for preparing packages of alkali metals suitable for addition to a melt of other metals because it avoids the danger of piping developing as a result of the penetration of gas bubbles in the metallurgical melt.

What is claimed is: l

1. A process for the gas-free packaging of a molten alkali metal in a can capable of accepting a clamp-on lid, said process comprising filling said can with said molten metal, applying a lid to said can, closing said can by clamping said lid to said can, inventing the resulting closed can so that the exposed surface of said lid faces downward, and cooling the inverted can.

2. Process of claim 1 in which the can is provided with a loosely fitting lid, inserting said can with said loosely fitting lid in a support, said support swivelable in at least a are, said support disposed in a heatable vacuum chamber, evacuating gas from said chamber while maintaining said alkali metal in molten form, solidifying said alkali metal, after swiveling the support 180, releasing vacuum in said chamber and clamping said lid on said can. 

1. A process for the gas-free packaging of a molten alkali metal in a can capable of accepting a clamp-on lid, said process comprising filling said can with said molten metal, applying a lid to said can, closing said can by clamping said lid to said can, inventing the resulting closed can so that the exposed surface of said lid faces downward, and cooling the inverted can.
 2. Process of claim 1 in which the can is provided with a loosely fitting lid, inserting said can with said loosely fitting lid in a support, said support swivelable in at least a 180* arc, said support disposed in a heatable vacuum chamber, evacuating gas from said chamber while maintaining said alkali metal in molten form, solidifying said alkali metal, after swiveling the support 180*, releasing vacuum in said chamber and clamping said lid on said can. 